The present invention relates generally to a new and novel fluid storage tank for mounting on a vehicle frame. More particularly, the present invention relates to a fluid storage tank which is capable of being readily mounted in a fold-down trailer or similar vehicle.
The concept of a fold-down trailer as a popular shelter for individuals and families when camping is well-known. Many people prefer a fold-down trailer because they provide a compact trailer when being towed, while at the same time are capable of providing expanded living area when the trailer is parked at a camp site or other convenient location. Fold-down trailers are generally lighter in weight than conventional trailers and also have less wind resistance when being towed due to its smaller exposed cross-sectional area. Thus, fold-down trailers generally provide better gasoline mileage for the towing vehicle than when towing most conventional camping trailers.
In order to quickly convert a fold-down trailer from its closed, compact traveling configuration to its opened, habitable configuration, a lifting mechanism is often provided. One common lifting mechanism includes a rotatable crank handle, often positioned on one side near the back of the trailer. The rotatable crank handle is attached through a gear assembly to a series of cables which extend longitudinally through the chassis of the fold-down trailer. The cables are attached to lifter posts, normally one positioned in each corner of the trailer. The lifter posts are attached to a collapsible tent portion of the fold-down trailer. The lifting mechanism thus allows the collapsible tent portion to be raised or lowered in response to the rotation of the crank handle.
It is sometimes desirable to have a fluid storage tank, often for storing drinking water, installed in a fold-down trailer. For example, when camping at many campgrounds, fresh water is not readily available, and it is beneficial to have a supply in the trailer. In the past, fluid storage tanks have been located in such locations as under dinette seats or in a cabinet under a kitchen sink. However, placing a fluid storage tank in these locations can present at least two difficulties. First, because of the compact size of the closed fold-down trailer, storage space is limited. Placing a fluid storage tank in these traditional locations prevents the areas from being utilized for other types of storage. Secondly, the proximity of the fluid storage tank to the trailer wheel and axle assembly can affect the towing characteristics of the fold-down trailers. This is particularly the case with fold-down trailers since with their light weight, the fluid can be a significant portion of the total weight of the fold-down trailer. The effect is increased because the fluid storage tank is often located a significant distance, both longitudinally away and vertically above, the wheel and axle assembly.
U.S. Pat. No. 4,728,144 to Crean for a Trailer Construction and U.S. Pat. No. 4,746,146 to Crean for Motorhomes both disclose the placement of fluid storage tanks on top of the chassis of a trailer and motor home, respectfully, above the wheel and axle assembly. In these patents, a series of joist members are utilized to elevate the floor of the living area. Fluid storage tanks are then positioned in the space between the vehicle chassis and the elevated floor. Because the overall height of a full-size trailer or motorhome can be readily increased to accommodate this elevated floor, this arrangement performs well in these types of units. However, in fold-down trailers, it is desirable to keep the overall height at a minimum, and, thus, the additional height required for an elevated floor is not readily available.
Attempts at placing a fluid storage tank below the floor in a fold-down camper have been difficult because it is normally desirable to place the floor directly on the top surface of the trailer chassis in order to minimize the overall height of the trailer. Thus, placement of the fluid storage tank below the floor can interfere with the wheel and axle assembly, chassis structural members and the lifting mechanism. These devices are usually included in this area, thus limiting the space available for a fluid storage tank.
It should be noted that many of the difficulties described for the placement of fluid storage tanks in fold-down trailers may also be present in other small trailers where the compact size limits the living and storage space available.
Accordingly, an object of the present invention is the provision of a fluid storage tank which is positioned substantially below the top surface of the vehicle chassis in order to maximize the amount of storage space available in the interior of the vehicle.
Another object of the present invention is to provide a fluid storage tank for a towable vehicle which is mounted in close proximity to the vehicle axle member in order to minimize the effect of varying fluid level and weight on the towing characteristics of the towable vehicle.
A further object of the present invention is to provide a fluid storage tank for a fold-down camping trailer which does not interfere with the lifting mechanism that converts a fold-down trailer from its closed, traveling configuration, to and from, its open, habitable configuration.
These and other objects of the present invention are attained by the provision of an enclosed fluid storage tank which is positioned substantially below the top surface of the vehicle chassis and is preferably mounted over the vehicle axle member. In some preferred embodiments, the fluid storage tank is capable of being mounted entirely below the top surface of the vehicle chassis. Preferably, the fluid storage tank is secured to the vehicle chassis between the floor covering and removable secondary longitudinal support members along two longitudinally extending ledges. In certain preferred embodiments, the fluid storage tank includes a vertically offset portion which provides clearance for the axle member and a clearance channel which provides clearance for lifting mechanism cables which extend through the vehicle chassis. The fluid storage tank also includes an access opening which provides access to the interior of the fluid storage tank and at least one, or preferably two, vents for venting the interior of the fluid storage tank as fluid is withdrawn.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.